Orthogonal frequency division multiple access (OFDMA) communications use an orthogonal frequency-division multiplexing (OFDM) digital modulation scheme to deliver information across broadband networks. OFDMA is particularly suitable for delivering information across wireless networks.
OFDMA-based communication systems are well known to have high peak-to-average power (PAPR) ratios. A high PAPR may reduce transmitter power amplifier (PA) power efficiency by increasing PA back off in order to comply with constraints imposed by regulatory spectral masks limit emissions outside of a designated frequency band.
Communication devices that operate under these transmission power constraints often employ multiple antennas to increase spatial diversity to improve the quality and reliability of a wireless link. For example, a communication device may employ a cyclic delay diversity (CDD) scheme that transmits a signal over a number of antennas with each transmitted signal being provided with a different degree of cyclic delay.
In another example, communication devices using distributed OFDMA allocations, e.g., uplink—partially used subchannel (UL-PUSC) schemes, may transmit different portions of a signal over different antennas. To provide CDD in these schemes, consecutive portions of the signal are interleaved over the different antennas.